Method:
Keep a big baking pan ready. Bundt pan preferable just for appearance sake. Heat oven to 160 degree Celsius.
Add sugar preferably in a metal pan and keep on medium flame. Don’t stir.
When the sugar starts to melt and caramelize, stir slowly so all sugar melts. When the mixture becomes golden in colour and starts to bubble, move the pan from fire and add hot water. Stir to melt the sugar and pour the hot caramel (minus 1 tbsp) to the baking pan kept ready.
After a while the caramel will crystallize in the pan. Now brush butter on the remaining areas of the baking pan and keep aside.

Cake:
Whisk flour, baking powder, baking soda and cocoa in a bowl.
In another large bowl, beat butter and sugar for a min. (I add 1 tbsp very hot water and beat again)
Add egg and mix.
Add flour alternating with buttermilk in 3 additions ending with flour.
Mix well and transfer the batter to the bundt pan.

Flan:
Add all ingredients in a blender and blend for 30 seconds so all ingredients are mixed well.
Pour on top of the cake batter. Its ok if the batter gets mixed. It will separate on baking.
Cover the bundt pan with aluminium foil.

Place a larger baking tray or cake pan in the oven and pour hot water and place the bundt pan inside this tray. Water should be atleast 1 -1 ½ “ high.
Bake for approx. 1 hr or until a toothpick inserted in the cake comes out clean.
Once done, remove from water bath and cool completely.
Refrigerate for few hrs but overnight preferable.
Before serving, place the cake pan in warm water for few mins (to cover bottom half).
Place the serving dish on top of the pan and invert the pan. The cake will slide down.
Pour all caramel sauce from the pan on top of the cake.
Serve and enjoy!

Notes:
Keep the cake refrigerated, but bring to room temperature before serving.